The prior art projectile includes a steel body member, and a steel cone, the body member having an axis and an exterior surface and a forward surface and a rearward side, and the tail cone having a front face connected to the rearward side and having an outer surface with a conical shape and an inner surface with a conical shape and a plurality of holes extending between the conical surfaces and being peripherially spaced.
The prior art projectile, which has a body member and a tail cone, is used with a selective cartridge in a smooth bore gun. The projectile, which is a range limiting type of projectile, has a cone with a plurality of holes for producing a projectile roll during flight, and for producing a choking off of the air stream as the velocity decays causing a high drag effect on the projectile to limit projectile range.
One problem with the prior art projectile is that the choking off of the air stream does not act uniformly at each of the holes, and the rate of velocity decay is variable, so that the vertical impact height on the target, as required, is adversely affected, and also impact dispersion is adversely affected. In addition, the mass of the steel tail cone causes the projectile to be marginally statically stable. Static stability is proportional to the separation between the projectile's center of gravity and its center of air stream pressure. Thus, a rearward center of gravity would reduce the static stability margin of the projectile.